Fluid-filled elastic mount having caulked portion for sealing off fluid chamber

ABSTRACT

A fluid-filled elastic mount including a first and a second support member elastically connected by an elastic body interposed between, a cylindrical connecting member secured to an outer surface of the elastic body, and a closure member fitted on the connecting member. The closure member cooperates with the elastic body to define a fluid chamber filled with a non-compressible fluid. The fluid chamber is divided by a partition structure supported by the closure member, into a pressure-receiving chamber and a variable-volume equilibrium chamber. A sealing rubber layer is sandwiched between the connecting and closure members, in a direction perpendicular to the load-receiving direction of the mount, assuring fluid-tight sealing of the fluid chamber. The second support member includes a caulking portion which retains the connecting and closure members in the load-receiving direction. A method of manufacturing the fluid-filled elastic mount as described above is also disclosed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a fluid-filled elastic mountadapted to dampen or isolate vibrations applied thereto, based on flowof a non-compressible fluid contained therein, and more particularly tosuch a fluid-filled elastic mount which exhibits excellentfluid-tightness of a fluid chamber filled with the fluid, assuring ahigh degree of durability. The invention is also concerned with a methodof manufacturing such a fluid-filled elastic mount as described above.

2. Discussion of the Prior Art

An elastic mount is known as a vibration damping member interposedbetween two members of a vibration system, for flexibly connecting thesetwo members. As one type of the elastic mount, there is known aso-called fluid-filled elastic mount as disclosed in laid-openPublication No. 57-9340 of unexamined Japanese Patent Application, whichhas a pressure-receiving chamber and a variable-volume equilibriumchamber which are filled with a suitable non-compressible fluid. Thepressure-receiving chamber is partially defined by an elastic body forflexibly connecting two support structures fixed to the above twomembers, and a pressure of the fluid in this chamber changes due toelastic deformation of the elastic body upon application of vibrationsto the mount. The equilibrium chamber is partially defined by a flexiblediaphragm, which allows a volumetric change of this chamber due to itselastic deformation, so as to avoid a pressure change of the fluidtherein. These pressure-receiving and equilibrium chambers communicatewith each other through an orifice passage. This fluid-filled elasticmount is capable of providing an excellent vibration damping effectwhich cannot be obtained by the elasticity of the elastic body alone,based on resonance of the fluid flowing through the orifice passage.Thus, the fluid-filled elastic mount of the above type is favorably usedas an engine mount for a motor vehicle, for example.

In manufacturing the fluid-filled elastic mount as disclosed in theabove-identified publication, a cylindrical connecting member is securedby vulcanization to an outer circumferential surface of the elasticbody, and an opening of the connecting member is fluid-tightly closed byan appropriate closure member, whereby a fluid chamber is formed betweenthe elastic body and the closure member. This arrangement facilitatesthe formation of the fluid chamber (i.e., the pressure-receiving andequilibrium chambers), and the filling of the fluid chamber with thefluid. To assure sufficient fluid-tightness of the fluid chamber formedin the elastic mount, it is required to provide a high degree offluid-tight seal between relevant engaging portions of the closuremember and the connecting member upon assembling thereof.

In the known fluid-filled elastic mount, the closure member and theconnecting member are assembled together by a caulking technique. Morespecifically, an open end portion or caulking portion of one of theseclosure and connecting members is caulked against an open end portion ofthe other member, so that the open end portion of the other member isgripped by the caulking portion of the above-indicated one member, inthe axial direction of the mount. In this manner, the closure member isassembled with the connecting member, with a sealing rubber layersandwiched between the engaging portions of these members, therebyassuring fluid-tight sealing between these portions.

In the fluid-filled elastic mount with the connecting and closuremembers assembled by the caulking technique, the vibrations are appliedbetween the connecting and closure members, in the axial direction inwhich the gripping force of the caulking portion of the above-indicatedone member is applied to the end portion of the other member. Therefore,the caulking engagement between the connecting and closure members maybe gradually loosened due to the applied vibrations, resulting inreduction in the gripping force of the caulking portion. Since theelastic mount of the above type relies on the gripping force of thecaulking portion for giving fluid-tight sealing between the connectingand closure members, the reduced gripping force tends to result indeterioration in fluid-tightness of the fluid chamber, causing a problemof leakage of the fluid from the fluid chamber. Thus, it is difficultfor the known fluid-filled elastic mount to have a sufficiently highdegree of durability.

SUMMARY OF THE INVENTION

It is therefore a first object of the present invention to provide animproved fluid-filled elastic mount which exhibits excellentfluid-tightness of a fluid chamber formed in the mount, assuringsufficient durability.

It is a second object of the invention to provide a method ofmanufacturing such a fluid-filled elastic mount as described above.

The first object may be attained according to one aspect of the presentinvention, which provides a fluid-filled elastic mount for flexiblyconnecting two members, comprising: (a) a first support member fixed toone of the two members to be flexibly connected; (b) an elastic bodyhaving a generally truncated conical shape and including asmall-diameter end portion and a large-diameter end portion, the firstsupport member being secured to the small-diameter end portion of theelastic body; (c) a cylindrical connecting member secured to an outercircumferential surface of the large-diameter end portion of the elasticbody; (d) a closure member having a generally cylindrical shape closedat one axial end, and including a cylindrical wall portion which isfitted on the connecting member such that an opening of the closuremember is fluid-tightly closed by the elastic body, the closure membercooperating with at least the elastic body to define a fluid chamberfilled with a non-compressible fluid; (e) a flexible diaphragm securedto the closure member so as to partially define the fluid chamber; (f) asealing rubber layer which is formed on at least one of an outercircumferential surface of the connecting member, and an innercircumferential surface of the cylindrical wall portion of the closuremember, such that the sealing rubber layer is sandwiched between theconnecting member and the closure member in a direction perpendicular toa load-receiving direction in which vibrations are applied to theelastic mount; (g) a second support member which is spaced apart fromthe first support member in the load-receiving direction, and fixed tothe other of the two members to be flexibly connected, the secondsupport member being fitted on the closure member and including acaulked portion which retains the connecting member and the closuremember in the load-receiving direction; (f) a partition structuresupported by the closure member so a to extend in a directionsubstantially perpendicular to the load-receiving direction, thepartition structure dividing the fluid chamber into a pressure-receivingchamber partially defined by the elastic body so that a pressure of thefluid in the pressure-receiving chamber changes due to elasticdeformation of the elastic body upon application of the vibrations inthe load-receiving direction, and an equilibrium chamber partiallydefined by the flexible diaphragm so that a volumetric change in theequilibrium chamber is allowed by elastic deformation of the flexiblediaphragm; and (g) means for defining an orifice passage for fluidcommunication between the pressure-receiving and equilibrium chambers.

In the fluid-filled elastic mount constructed as described aboveaccording to the present invention, the connecting member secured to theouter circumferential surface of the elastic body is assembled with theclosure member which cooperates with the elastic body to define thefluid chamber (pressure-receiving and equilibrium chambers), such thatfluid-tight sealing between the connecting and closure members isestablished with the sealing rubber layer sandwiched by and between thefacing surfaces of the two members which are opposed to each other inthe direction perpendicular to the load-receiving direction. In thisarrangement, the sealing rubber layer is pressed by the connecting andclosure members in the direction perpendicular to the load-receivingdirection in which the vibrations are applied between these members.Accordingly, the present fluid-filled engine mount does not suffer fromreduction in the fluid-tightness of the fluid chamber filled with thefluid, and exhibits excellent durability.

The second object may be attained according to another aspect of theinvention, which provides a method of manufacturing the fluid-filledelastic mount as defined above, comprising the steps of: (a) preparingan inner unit consisting of the first support member, the elastic bodyan the connecting member, such that the first support member is securedto the small-diameter end portion of the elastic body, and such that theconnecting member is secured to the outer circumferential surface of thelarge-diameter end portion of the elastic body; (b) preparing theclosure member having the cylindrical wall portion to be fitted on theconnecting member, the cylindrical wall portion having a diameter whichgradually increases toward the opening of the closure member, thesealing rubber layer being formed on the inner circumferential surfaceof the cylindrical wall portion of the closure member; (c) preparing thepartition structure so that the orifice passage is defined by thepartition structure; (d) disposing the cylindrical wall portion of theclosure member radially outwardly of the connecting member, with aperipheral portion of the partition structure interposed between theclosure member and the connecting member in an axial direction of theelastic mount, and subsequently drawing the cylindrical wall portion ofthe closure member radially inwards so that the cylindrical wall portionis forced against the outer circumferential surface of the connectingmember with the sealing rubber layer sandwiched therebetween, wherebythe partition structure is supported by the closure member and theconnecting member, such that the pressure- receiving chamber and thevariable-volume equilibrium chamber are formed on the opposite sides ofthe partition member; and (e) fitting the caulked portion of the secondsupport member on the cylindrical wall portion of the closure member,such that the caulked portion is caulked to retain the cylindrical wallportion and the connecting member in the axial direction of the mount.

According to the method of the present invention, the cylindrical wallportion of the closure member which is to be fitted on the connectingmember is first formed in tapered configuration, thereby making it easyto position the cylindrical wall portion radially outwardly of theconnecting member. Thereafter, the cylindrical wall portion of theclosure member is caulked or drawn, so that the wall portion is easilypress-fitted on the outer circumferential surface of the connectingmember. Thus, according to the present method, the assembling of theclosure member with the connecting member can be easily achieved,assuring significantly improved efficiency in the manufacture of thefluid-filled elastic mount.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the presentinvention will become more apparent by reading the following descriptionof a presently preferred embodiment of the invention, when considered inconnection with the accompanying drawings, in which:

FIG. 1 is an elevational view in axial cross section of one embodimentof a fluid-filled elastic mount of the present invention in the form ofan engine mount for a motor vehicle;

FIG. 2 is an axial cross sectional view showing an inner unit of theengine mount of FIG. 1, which is prepared by vulcanization of anunvulcanized rubber material to form an elastic body of the mount;

FIG. 3 is an axial cross sectional view showing a closure member of theengine mount of FIG. 1;

FIG. 4 is an axial cross sectional view showing a partition structure ofthe engine mount of FIG. 1;

FIG. 5 is an elevational view in axial cross section, illustrating theinner unit as assembled with the closure member and the partitionmember;

FIG. 6 is an axial cross sectional view showing a second support emberof the engine mount of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring first to FIG. 1 showing a vehicle engine mount 10 as oneembodiment of the fluid-filled elastic mount of this invention,reference numerals 12 and 14 denote a first and a second rigid supportmember, respectively. These first and second support members 12, 14 arespaced apart from each other by a suitable distance in a load-receivingdirection in which vibrations are received by the engine mount 10.Between the first and second support members 12, 14, there is formed anelastic body 16 so that the two members 12, 14 are elastically connectedto each other by the elastic body 16. The engine mount 10 has apressure-receiving chamber 20 and a variable-volume equilibrium chamber22 formed therein, and an orifice passage 18 for fluid communicationbetween the two chambers 20, 22. The engine mount 10 is installed on avehicle such that the first support member 12 is fixed to an engine unitof the vehicle while the second support member 14 is fixed to a body ofthe vehicle, whereby the engine unit is flexibly mounted on the vehiclebody. In this condition, the engine mount 10 provides a high vibrationdamping effect due to flow of a fluid through the orifice passage 18,with respect to vibrations applied in the direction in which the firstand second support members 12, 14 are opposed to each other, i.e., inthe vertical direction as viewed in FIG. 1.

More specifically, the elastic body 16 assumes a generally truncatedconical shape, and has a cavity 24 which is open in the large-diameterend face thereof. As shown in FIG. 2, the lower portion of the firstsupport member 12 is secured by vulcanization to the small-diameter endportion of the elastic body 16. On the other hand, a cylindricalconnecting member 26 is secured by vulcanization to the outercircumferential surface of the large-diameter end portion of the elasticbody 16. Thus, the elastic body 16, the first support member 12 and theconnecting member 26 are assembled together by means of vulcanization,to thereby provide an inner unit 28 as shown in FIG. 2.

The first support member 12 of the inner unit 28 is a solid rod-likemember made of metal, and is formed integrally with a stopper portion 30which protrudes radially outwards from the axially intermediate portionof the member 12. The first support member 12 also includes a taperedportion 32 which forms a greater part of the lower half thereof andwhose diameter gradually decreases toward one of the axially oppositeends of the member 12. The first support member 12 is secured to theelastic body 16 with the tapered portion 32 axially embedded in thesmall-diameter end portion of the elastic body 16. On the stopperportion 30 of the first support member 12, there is formed a suitablethickness of a rubber layer 36 as an integral part of the elastic body16. The first support member 12 further has a threaded or tapped hole 34which is open on the other axial end remote from the .tapered portion32, and at which the support member 12 is fixed to the engine unit ofthe vehicle.

As shown in FIG. 1, the inner unit 28 is assembled with a generallycylindrical closure member 38 closed at one axial end, such that theclosure member 38 is fitted on the large-diameter portion of the elasticbody 16, and is fixed to the outer surface of the connecting member 26.Referring to FIG. 3, the closure member 38 has a stepped cylindricalwall including a shoulder portion 40 formed at the axially intermediateportion thereof, and a small-diameter and a large-diameter portion 42,44 formed on the opposite sides of the shoulder portion 40. The closuremember 38 is open at one axial end of the large-diameter portion 44, andthe small-diameter portion 42 has an open end 46. A thin-walled flexiblediaphragm 48 made of a rubber material is secured by vulcanization tothe inner surface of the closure member 38 so as to close the open end46, as shown in FIG. 3. Further, a sealing rubber layer 50 having asuitable thickness is fixedly formed over substantially the entire areaof the inner circumferential surface of the large-diameter portion 44 ofthe closure member 38.

The inner unit 28 is assembled with the closure member 38 such that thelarge-diameter portion 44 of the closure member 38 is fixedly fitted onthe outer surface of the connecting member 26 of the inner unit 28. Inthis condition, the sealing rubber layer 50 is sandwiched (underpressure) between the large-diameter portion 44 of the closure member38, and the connecting member 26, such that the members 38, 26 aresuperposed on the rubber layer 50 in the radial direction of the mount.In this arrangement, the opening of the closure member 38 isfluid-tightly closed by the inner unit 28, assuring fluid-tight sealingbetween the closure member 38 and the connecting member 26.

As is apparent from FIG. 3, the large-diameter portion 44 of the closuremember 38 is originally tapered such that the diameter of the sameportion 44 gradually increases toward the open end of the closure member38. As shown in FIG. 5, the large-diameter end portion of the elasticbody 16 wit the connecting member 26 is received in the large-diameterportion 44 of the closure member 38. Then, the large-diameter portion 44is subject to a drawing operation so that the same portion 44 is fixedlyfitted on the outer surface of the connecting member 26. Namely, theoriginal tapered shape of the large-diameter portion 44 facilitatesinsertion of the elastic body 16 and the connecting member 26 into thesame portion 44, and also facilitates the drawing operation as describedabove.

Within the closure member 38, there is accommodated partition means inthe form of a generally circular partition structure 52, which includesgenerally hat-shaped first and second partition members 54, 56 that aresuperposed on each other in the axial direction of the engine mount 10,as shown in FIG. 4. The orifice passage 18 indicated above is formed ina radially outer or peripheral portion of the partition structure 52, soas to extend a suitable length in the circumferential direction of themount 10, between the facing surfaces of cylindrical walls of the firstand second partition members 54, 56. In a radially inner portion of thepartition structure 52, there is formed a generally flat space 66 whichis defined between bottom walls of the first and second partitionmembers 54, 56, and which accommodates a flexible film 60 made of arubber material, for example. The flat space 66 is divided into twosections by the flexible film 60.

The partition structure 52 described above is inserted within theclosure member 38, prior to assembling of the closure member 38 with theinner unit 28. Thereafter, the closure member 38 is assembled with theinner unit 28, so that the partition structure 52 is retained at itsouter peripheral portion by and between the shoulder portion 40 of theclosure member 38 and the corresponding axial end of the connectingmember 26, as shown in FIG. 5. Thus, the partition structure 52 isfixedly supported by the connecting and closure members 26, 38 so as togenerally extend within the closure member 38 in a directionsubstantially perpendicular to the axis of the engine mount 10.

The partition structure 52 provided as described above serves to dividethe space defined by the closure member 38 and the inner unit 28, intotwo axially opposite sections, that is, the pressure-receiving chamber20 formed on the side of the first support member 12, and theequilibrium chamber 22 formed on the side of the flexible diaphragm 48.The pressure-receiving chamber 20 is partially defined by the elasticbody 16, whereby a pressure of the fluid in the chamber 20 varies due tothe deformation of the elastic body 16 upon application of vibrations tothe engine mount 10, based on the deformation of the elastic body 16. Onthe other hand, the equilibrium chamber 22 is partially defined by theflexible diaphragm 48, which allows a volumetric change of theequilibrium chamber 22 due to its elastic deformation, to thereby absorba pressure change in this chamber 22.

The fluid filling the pressure-receiving and equilibrium chambers 20, 22is a suitable non-compressible fluid such as water, alkylene glycol,polyalkylene glycol or silicone oil. The filling of thepressure-receiving and equilibrium chambers 20, 22 with such anon-compressible fluid is accomplished by assembling the closure member38 and partition structure 52 with the inner unit 28, within a mass ofthe fluid.

The orifice passage 18 formed in the radially outer portion of thepartition structure 52 communicates at its opposite ends with thepressure-receiving chamber 20 and the equilibrium chamber 22,respectively, so that the fluid is allowed to flow between the twochambers 20, 22 through the orifice passage 18. The flat space 66 formedin the radially inner portion of the partition structure 52 alsocommunicates at one of the two sections thereof with thepressure-receiving chamber 20, and at the other section with theequilibrium chamber 22, through holes formed through the bottom walls ofthe partition members 54, 56. Accordingly, the pressures of the fluidmasses in the pressure-receiving and equilibrium chambers 20, 22 act onthe opposite major surfaces of the flexible film 60, whereby the fluidis substantially allowed to flow between the pressure-receiving andequilibrium chambers 20, based on elastic deformation or displacement ofthe flexible film 60.

The cross sectional area, length, and other parameters of the orificepassage 18 are suitably determined so that the engine mount 10 providesa comparatively high damping effect for the input vibrations in a lowfrequency range, such as engine shakes, based on flow of the fluidthrough the orifice passage 18. Further, the size of the holes whichcommunicate with the flat space 66 and pressure-receiving chamber 20,and the elasticity of the flexible film 60, for example, are suitablydetermined so that the engine mount 10 exhibits a sufficiently lowdynamic spring constant with respect to the input vibrations in a highfrequency range, such as booming noise, based on the fluid flows withinthe flat space 66 due to the elastic deformation of the flexible film60.

The second support member 14 indicated above is secured to the assemblyof the inner unit 28 and the closure member 38, such that the supportmember 14 is fitted on the outer circumferential surface of the closuremember 38. This second support member 14 assumes a generally cylindricalshape closed at one axial end as shown in FIG. 6, and has a larger wallthickness and greater dimensions than those of the closure member 38.Like the closure member 38, the second support member 14 has a steppedcylindrical wall including a shoulder portion 68 formed at the axiallyintermediate portion thereof, and a small-diameter and a large-diameterportion 70, 72 formed on the opposite sides of the shoulder portion 68.The second support member 14 has an opening at one axial end of thelarge-diameter portion 72. The second support member 14 has a bottomwall through which is formed a through-hole 80 which permits theinterior of the support member 14 to communicate with the ambientatmosphere.

The second support member 14 described above is fitted on the closuremember 38 so as to cover the same, as shown in FIG. 1. Subsequently, anopen end portion of the large-diameter portion 72 of the second supportmember 14 is bent so as to provide an inward flange 72a which extendsradially inwards from the axial open end of the support member 14. Inthis manner, the second support member 14 is caulked against the closuremember 38, such that the large-diameter portion 44 of the closure member38 and the connecting member 26 are axially retained by and between theshoulder portion 68 and the inward flange 72a of the large-diameterportion 72 of the support member 14. Namely, the connecting member 26 isfixed to the large-diameter portion 44 of the closure member 38 bycaulking of the second support member 14 with respect to the closuremember 38. In this case, the connecting member 26 is prevented fromslipping off in the axial direction away from the closure member 38. Itwill be understood from the above description that in the instantembodiment, the large-diameter portion 72 and the shoulder portion 68 ofthe second support member 14 constitute a caulked portion whichfunctions to fix the connecting member 26 to the closure member 38.

As illustrated in FIGS. 1 and 6, a generally annular mounting bracket 82is fitted on and welded to the small-diameter portion 70 of the secondsupport member 14, such that the bracket 82 extends radially outwardsfrom the support member 14. This mounting bracket 82 has a plurality ofmounting holes 84 formed therethrough, and a corresponding number ofnuts 86 welded to its portions through which the mounting holes 84 areformed. Upon installation of the elastic mount in position, the mountingbracket 82, and the second support member 14, are fixed to the vehiclebody by means of bolts screwed to the nuts 86 through the holes 84.

Radially outwardly of the first support member 12, there is disposed agenerally cylindrical stopper member 74 made of metal, which surroundsthe lower portion of the first support member 12 embedded in the elasticbody 16. The stopper member 74 has an outward flange 76 formed at one ofits axially opposite open ends which is nearer to the second supportmember 14. The stopper member 74 is fixedly attached to the secondsupport member 14, such that the outward flange 76 is gripped by andbetween the caulked inward flange 72a of the second support member 14,and the corresponding ends of the closure member 38 and the connectingmember 26.

The stopper member 74 extends from the second support member 14 towardthe first support member 12 in the axial direction of the mount, and isprovided with an inward flange 78 formed at the axial open end thereofremote from the second support member 14. The inner flange 78 extendsradially inwards, i.e., toward the first support member 12. The inwardflange 78 is located axially outwardly of the stopper portion 30 of thefirst support member 12. With the engine mount 10 installed in place onthe vehicle, the weight of the engine unit acts on the first supportmember 12, causing the elastic body 16 to be compressively deformed,whereby the inward flange 78 of the stopper member 14 is spaced from thestopper portion 30, with a suitable axial spacing therebetween. In thiscondition, the amount of relative displacement of the first and secondsupport members 12, 14 in the direction away from each other, and theamount of resultant deformation of the elastic body 16 are limited byabutting contact of the inward flange 78 with the stopper portion 30through the rubber layer 36.

As described above, the thus constructed engine mount 10 is interposedbetween the engine unit and the vehicle body, such that the first andsecond support members 12, 14 are respectively fixed to the engine unitand the vehicle body. In operation, a vibrational load is applied to theengine mount 10 thus installed, primarily in the direction in which thefirst and second support members 12, 14 are opposed to each other.

The vibrational load applied between the first and second supportmembers 12, 14 is applied between the connecting member 26 secured tothe outer circumferential surface of the elastic body 16, and thelarge-diameter portion 44 of the closure member 38 fitted on theconnecting member 26, so as to cause shearing stresses in the axialdirection of the mount between the connecting member 26 and thelarge-diameter portion 44. In this engine mount 10, the fluid-tightsealing between the connecting member 26 and the large-diameter portion44 of the closure member 38 is secured by the sealing rubber layer 50,which is sandwiched between the members 26, 44 in the directionperpendicular to the axis of the mount. It follows that the vibrationalload is applied to the engine mount 10 in the direction perpendicular tothe direction in which the connecting member 26 and the closure member38 are forced against the sealing rubber layer 50 for the fluid-tightsealing therebetween.

Accordingly, the vibrational load applied to the engine mount 10 willnot directly cause any deformation of the connecting and closure members26, 38, which may result in deterioration of the fluid-tight sealingbetween these members 26, 38. This means that the engine mount 10 doesnot suffer from reduction in fluid-tightness with respect to thenon-compressible fluid contained therein. Thus, the instant engine mount10 is able to maintain its initial fluid-tightness for the fluidcontained therein, assuring a high degree of durability.

Further, the engine mount 10 as described above does not suffer fromreduction in the fluid-tightness for the fluid contained therein, evenif the caulked portion of the second support member 14 is loosened ordeformed, for example. Therefore, even where the stopper member 74 issupported by the caulked portion of the second support member 14 as inthe instant embodiment, the engine mount 10 is free from reduction inits fluid-tightness, which may otherwise occur due to a shock applied tothe calked portion through the stopper member 74 upon abutting contactof the flange 78 with the stopper portion 30 to limit relativedisplacement between the first and second support members 12, 14.

In manufacturing the thus constructed engine mount 10, thelarge-diameter portion 44 of the closure member 38 is formed in taperedconfiguration, and is disposed radially outwardly of the connectingmember 26. Then, the drawing operation is effected to caulk thelarge-diameter portion 44 against the outer circumferential surface ofthe connecting member 26. Thus, the operation for press-fitting thelarge-diameter portion 44 on the connecting member 26 can be easilyaccomplished, assuring significantly improved efficiency in themanufacture of the engine mount 10.

While the present invention has been described in its presentlypreferred embodiment, for illustrative purpose only, it is to beunderstood that the invention is not limited to the precise details ofthe illustrated embodiment.

In the illustrated embodiment, the sealing rubber layer 50 adapted tofunction as a fluid-tight seal between the connecting member 26 and theclosure member 38 is formed on the inner circumferential surface of theclosure member 38. However, such a sealing rubber layer may be formed onthe outer circumferential surface of the connecting member 26, inaddition to or in place of the sealing rubber layer 50.

In the illustrated embodiment, the stopper member 74 is fixedlysupported by the caulked portion of the second support member 14.However, the stopper member 74 may be eliminated from the fluid-filledelastic mount of the invention.

While the second support member 14 of the illustrated embodiment takesthe form of a generally cylindrical member closed at one axial end, thesecond support member 14 may be a cylindrical member which isconstituted by a cylindrical member which is caulked to retain theconnecting member 26 and the closure member 38, in the axial directionof the mount.

The construction of the partition structure 52, and the construction forsupporting the partition structure 52 with respect to the closure member38 are not limited to those of the illustrated embodiment.

Further, the method of manufacturing the fluid-filled elastic mountaccording to the present invention is by no means confined to that ofthe illustrated embodiment. For example, the closure member 38 may beformed as a non-tapered cylindrical member having a larger diameter thanthe connecting member 26. In this case, the closure member 38 is firstdisposed radially outwardly of the connecting member 26, and the closuremember 38 is then drawn to reduce its diameter so that the closuremember 38 is fitted on the outer circumferential surface of theconnecting member 26.

It will be understood that the invention may be embodied with variousother changes, modifications and improvements which may occur to thoseskilled in the art, without departing from the spirit and scope of theinvention defined in the following claims.

What is claimed is:
 1. A fluid-filled elastic mount for flexiblyconnecting two members, comprising:a first support member fixed to oneof the two members to be flexibly connected; an elastic body having agenerally truncated conical shape and including a small-diameter endportion and a large-diameter end portion, said first support memberbeing secured to said small-diameter end portion of said elastic body; acylindrical connecting member secured to an outer circumferentialsurface of said large-diameter end portion of said elastic body; aclosure member having a generally cylindrical shape, and including afirst and a second cylindrical wall portion, said first cylindrical wallportion being fitted on said connecting member such that an opening ofsaid second cylindrical wall portion is fluid-tightly closed by saidelastic body, said second cylindrical wall portion cooperating with atleast said elastic body to define a fluid chamber filled with anon-compressible fluid; a flexible diaphragm secured to said secondcylindrical wall portion of said closure member so as to partiallydefine said fluid chamber; a sealing rubber layer which is formed on atleast one of an outer circumferential surface of said connecting member,and an inner circumferential surface of said first cylindrical wallportion of said closure member, such that said sealing rubber layer issandwiched between said connecting member and said closure member in adirection perpendicular to a load-receiving direction in whichvibrations are applied to the elastic mount; a second support memberwhich is spaced apart from said first support member in saidload-receiving direction, and fixed to the other of said two members tobe flexibly connected, said second support member being fitted on saidclosure member and including a caulked portion which retains saidconnecting member and said first cylindrical wall portion of saidclosure member in said load-receiving direction; a partition structuresupported by said closure member so as to extend in a directionsubstantially perpendicular to said load-receiving direction, saidpartition structure dividing said fluid chamber into apressure-receiving chamber partially defined by said elastic body sothat a pressure of the fluid in said pressure-receiving chamber changesdue to elastic deformation of said elastic body upon application of thevibrations in said load-receiving direction, and an equilibrium chamberpartially defined by said second cylindrical wall portion and saidflexible diaphragm so that a volumetric change in said equilibriumchamber is allowed by elastic deformation of said flexible diaphragm;and means for defining an orifice passage for fluid communicationbetween said pressure-receiving and equilibrium chambers.
 2. Afluid-filled elastic mount according to claim 1, wherein said closuremember has a stepped cylindrical wall consisting of a large-diameterportion as said first cylindrical wall portion, a small-diameter portionas said second cylindrical wall portion, and a shoulder portion betweensaid large-diameter and small-diameter portions, said large-diameter endportion of said elastic body with said connecting member being receivedin said large-diameter portion of said closure member.
 3. A fluid-filledelastic mount according to claim 2, wherein said second support memberhas a stepped cylindrical wall consisting of a large-diameter portion, asmall-diameter portion and a shoulder portion, which respectivelycorrespond to said large-diameter portion, said small-diameter portionand said shoulder portion of said closure member, said large-diameterportion of said second support member including an inward flange whichis caulked so as to extend radially inwards, said caulked portionconsisting of said shoulder portion and said large-diameter portion ofsaid second support member.
 4. A fluid-filled elastic mount according toclaim 1, wherein said sealing rubber layer is formed on said innercircumferential surface of said first cylindrical wall portion of saidclosure member.
 5. A fluid-filled elastic mount according to claim 1,wherein said elastic body has a cavity formed in said large-diameter endportion, to provide at least a part of said pressure-receiving chamber.6. A fluid-filled elastic mount for flexibly connecting two members,comprising:a first support member fixed to one of the two members to beflexibly connected; an elastic body having a generally truncated conicalshape and including a small-diameter end portion and a large-diameterend portion, said first support member being secured to saidsmall-diameter end portion of said elastic body; a cylindricalconnecting member secured to an outer circumferential surface of saidlarge-diameter end portion of said elastic body; a closure member havinga generally cylindrical shape closed at one axial end, and including acylindrical wall portion which is fitted on said connecting member suchthat an opening of said closure member is fluid-tightly closed by saidelastic body, said closure member cooperating with at least said elasticbody to define a fluid chamber filled with a non-compressible fluid; aflexible diaphragm secured to said closure member so as to partiallydefine said fluid chamber; a sealing rubber layer which is formed on atleast one of an outer circumferential surface of said connecting member,and an inner circumferential surface of said cylindrical wall portion ofsaid closure member, such that said sealing rubber layer is sandwichedbetween said connecting member and said closure member in a directionperpendicular to a load-receiving direction in which vibrations areapplied to the elastic mount; a second support member which is spacedapart from said first support member in said load-receiving direction,and fixed to the other of said two members to be flexibly connected,said second support member being fitted on said closure member andincluding a caulked portion which retains said connecting member andsaid cylindrical wall portion of said closure member in saidload-receiving direction; and a partition structure supported by saidclosure member so as to extend in a direction substantiallyperpendicular to said load-receiving direction, said partition structuredividing said fluid chamber into a pressure-receiving chamber partiallydefined by said elastic body so that a pressure of the fluid in saidpressure-receiving chamber changes due to elastic deformation of saidelastic body upon application of the vibrations in said load-receivingdirection, and an equilibrium chamber partially defined by said flexiblediaphragm so that a volumetric change in said equilibrium chamber isallowed by elastic deformation of said flexible diaphragm; saidpartition structure comprising a first and a second partition memberwhich are superposed on each other in said load-receiving direction andwhich define an orifice passage in a circumferential direction of saidpartition structure, for fluid communication between saidpressure-receiving and equilibrium chambers.
 7. A fluid-filled elasticmount according to claim 6, wherein said first and second partitionmembers cooperate with each other to define a flat space, said elasticmount further comprising a flexible film which is supported by saidpartition structure and is deformably disposed within said flat space,so as to divide said flat space into two sections which communicate withsaid pressure-receiving chamber and said equilibrium chamber.
 8. Afluid-filled elastic mount for flexibly connecting two members,comprising:a first support member fixed to one of the two members to beflexibly connected; an elastic body having a generally truncated conicalshape and including a small-diameter end portion and a large-diameterend portion, said first support member being secured to saidsmall-diameter end portion of said elastic body; a cylindricalconnecting member secured to an outer circumferential surface of saidlarge-diameter end portion of said elastic body; a closure member havinga generally cylindrical shape closed at one axial end, and including acylindrical wall portion which is fitted on said connecting member suchthat an opening of said closure member is fluid-tightly closed by saidelastic body, said closure member cooperating with at least said elasticbody to define a fluid chamber filled with a non-compressible fluid; aflexible diaphragm secured to said closure member so as to partiallydefine said fluid chamber; a sealing rubber layer which is formed on atleast one of an outer circumferential surface of said connecting member,and an inner circumferential surface of said cylindrical wall portion ofsaid closure member, such that said sealing rubber layer is sandwichedbetween said connecting member and said closure member in a directionperpendicular to a load-receiving direction in which vibrations areapplied to the elastic mount; a second support member which is spacedapart from said first support member in said load-receiving direction,and fixed to the other of said two members to be flexibly connected,said second support member being fitted on said closure member andincluding a caulked portion which retains said connecting member andsaid cylindrical wall portion of said closure member in saidload-receiving direction; a partition structure supported by saidclosure member so as to extend in a direction substantiallyperpendicular to said load-receiving direction, said partition structuredividing said fluid chamber into a pressure-receiving chamber partiallydefined by said elastic body so that a pressure of the fluid in saidpressure-receiving chamber changes due to elastic deformation of saidelastic body upon application of the vibrations in said load-receivingdirection, and an equilibrium chamber partially defined by said flexiblediaphragm so that a volumetric change in said equilibrium chamber isallowed by elastic deformation of said flexible diaphragm; means fordefining an orifice passage for fluid communication between saidpressure-receiving and equilibrium chambers; and a stopper member whichis fixed to said second support member so as to extend toward said firstsupport member, said stopper member limiting an amount of relativedisplacement between said first and second support members.
 9. A methodof manufacturing a fluid-filled elastic mount for flexibly connectingtwo members, comprising the steps of:assembling an inner unit consistingof a first support member, an elastic body and a connecting member, suchthat said first support member is secured to a small-diameter endportion of said elastic body, and such that said connecting member issecured to an outer circumferential surface of a large-diameter endportion of said elastic body; providing a closure member having agenerally cylindrical shape closed at one axial end thereof andincluding a cylindrical wall portion to be fitted on said connectingmember, said cylindrical wall portion having a diameter which graduallyincreases toward said opening of said closure member; forming a sealingrubber layer on an inner circumferential surface of said cylindricalwall portion of said closure member; providing a partition structurehaving an orifice passage defined therein; assembling said cylindricalwall portion of said closure member radially outwardly of saidconnecting member, with a peripheral portion of said partition structurebeing interposed between said closure member and said connecting memberin an axial direction of the elastic mount, and subsequently drawingsaid cylindrical wall portion of said closure member radially inward sothat said cylindrical wall portion is forced against said outercircumferential surface of said connecting member with said sealingrubber layer sandwiched therebetween, whereby said partition structureis supported by said closure member and said connecting member to definea pressure-receiving chamber and a variable-volume equilibrium chamberon opposite sides of said partition member; and fitting a caulkedportion of a second support member on said cylindrical wall portion ofsaid closure member, such that said caulked portion is caulked to retainsaid cylindrical wall portion and said connecting member in said axialdirection of the mount.